From: Igor Zhbanov <i.zhbanov@samsung.com>
Date: Tue, 15 Oct 2013 10:35:13 +0000 (+0400)
Subject: Fix for SIGSEGV in systemd-bootchart on short-living processes
X-Git-Tag: v209~1876
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=306e6650221d88b29831bcdcef94447afb65df5c

Fix for SIGSEGV in systemd-bootchart on short-living processes

The function svg_ps_bars() dereferencess NULL pointer in the line
	endtime = ps->last->sampledata->sampletime;
because of partially initialized ps_struct (ps->last == NULL).

If some process terminates between scaning /proc directory in the log_sample()
function and reading additional information from /proc/PID/... files,
the files couldn't be read, the loop will be continued and partially
initialized structure returned.
---

diff --git a/src/bootchart/store.c b/src/bootchart/store.c
index f8c97c232..7f86cfe97 100644
--- a/src/bootchart/store.c
+++ b/src/bootchart/store.c
@@ -275,7 +275,7 @@ schedstat_next:
                         pscount++;
 
                         /* mark our first sample */
-                        ps->first = ps->sample;
+                        ps->first = ps->last = ps->sample;
                         ps->sample->runtime = atoll(rt);
                         ps->sample->waittime = atoll(wt);